The search for three men who went missing on the Mississippi River when two barge towing vessels collided has been suspended, the U.S. Coast Guard said Monday night.

The Coast Guard said the agency searched over 835 nautical miles (1,545 kilometers) for the missing mariners who were aboard the RC Creppel, news outlets reported.

Two vessels collided Sunday morning near Luling, Louisiana, temporarily closing the river to vessel traffic, according to the Coast Guard. The towing vessel, RC Creppel, sank, and three crew members went missing. A fourth person aboard the vessel was rescued by a private boater.

The agency began permitting one boat at a time to travel between Destrehan and Hahnville earlier on Monday even as the search for the missing mariners continued. The search was suspended hours later.

The Coast Guard did not release the names of the missing mariners.

The RC Creppel was pushing two barges carrying sulfuric acid, and the barges broke away during the accident. One of those barges was damaged in the incident and reportedly released a small amount of vapor into the air, the Coast Guard said.

Officials said the release was later secured, and they were not concerned about any potential health risks.